The present invention relates to three- and four-dimensional medical imaging. Artifacts due to a mechanically rocked array or movement are reduced for volume medical imaging.
In medical diagnostic ultrasound imaging, mechanically rocked arrays are used to acquire information representing a three-dimensional volume. A linear array of elements is mechanically rocked in an elevation dimension to scan different planes within a volume. Acoustic energy is electronically steered along an azimuth dimension for scanning within each of the elevationally spaced planes. Since the array moves over time, the beginning and ending transmit beams within a given elevation plane are offset in the elevation dimension. As a result, a motion artifact is generated when the acquired ultrasound data is used for generating a three-dimensional representation. Where the mechanical velocity is low, the motion artifact is limited. Four dimensional imaging or the generation of a sequence of three-dimensional images representing a volume over time is desired in medical diagnostic ultrasound. For rapidly acquiring data representing a three-dimensional volume, a motion artifact becomes more substantial.